Mercurial pressure gauge



Aug. 20, 1935.

F. cossoR MERCURIAL PRESSURE GAUGE Filed Nov. 22, 1934 INVENTOR Y A TTORIVE 1. 12,011,928 MEBCUBIAL Pimssumt cr tics Frank Cossor, London, England Application November 22,,

1934, s riamd, 754,214

In Great Britain November 1, 1934 v 20mins, (01.73-31) r t In the specification of my Letters Patent No.-

395,153 is described a mercurial pressure gauge in the form of a U-tube or the like, one limb of which is formed as a cistern and the other limb f relatively to one another and to the associated as a pressure tube, whilst avalve is providedlbe- 5 tween the cistern and the pressure tube,said valve being operable manually or automatically as the device is opened or closed. The object of the present invention is to provide improved means for manual operation of the valve.

To this end and in accordance with the present invention the valve provided between the cistern and the pressure tube of such a gauge is adapted to be opened, by longitudinal movement oi the pressure tube brought about by means of ascrew cap which is adapted to close that end of the tube 7 remote from the cistern.- 7 a Preferably the screw cap is formed differential- I 1y at its opposite ends so that when oneend" is screwed on to the casing of the gauge, it will bear "against the adjacent end of. the pressure tube, and move said tubelongitudinally to open the valve, whilst when the other end of the cap is screwed onto the casing asfar as possible, a part of it is brought close enough to the adjacent end of the pressure tube tofpreventundue movement of the tube, but without bringing about longitudinal movement of the tubeto open said,v

valve.

The accompanying drawing illustrates one form of mercurial pressure gauge made in accordance with this invention, Figure- 1 showing the valve closed and Figure 2 showingthe valve open, whilst Figures 3 and 4 are'sectional views of the valveandscrew cap, respective1y,,on a

larger scale.' l 3 a is the toner the casing of the instrument, and b is the base thereof which has integral therewith a cisternc. The base b is formed with a seat d for a valve 6 which is urged thereagainst I I by a spring I which abuts against a plug'gfi screwed intothebasebs Y 1 The cistern 0 leads by a passage h to the valve chamber'and the valve e has at its upper side a tubular projection i laterally apertured as at -7' and adaptedto be engaged by the adjacent end of the pressure tube when said tube It is forced downwards the valve 6 is opened toestablish connection between the cistern 0 and thepressure tube It as shown in Figure 2, whilst when said pressure tube is permitted to move upwards seat at as shown in Figure 1.

Such movement of the pressure tube 7c is effected by means of a cap m either end of which may end this cap m is formed n and an external shoulder'o saidshoulder o and into the top a of inthe instrument. At its other end,

washer s the face the instrument untilthe pressure cap m is valve e has been openedfully.

k of the instrument, so that V the valve e closes against its be screwed into the top act the casing. At one with an internal recess the bottom q of saidrecess n being so situated parts that when that end of the cap m is screwed the casing of "the instrument until the shouldero abuts against said topaa, as

, indicated in'Fig'ure 1, the end wall q of the recess alias? nwill not bear against the adjacent end of the pressure tube 10, but will be so close thereto as to v prevent undue endwise movement of said tube the cap is formed with an at the bottom of which is a of whichis so situated relatively to the external screw threading that said end of the cap m may be screwed into the'top a of tube It is forced downwards, thus forcing down and opening the valve e as indicated in Figures 2 and 3 which show that the lateral aperture 7' of the tubular projecw tion iis brought below the level of the valve seat internal recess ,7

cl thus enabling connection to be established between thecistern c and the pressure tube It, 2 whereupo'n mercury flows from said cistern into said tube to a common level as indicated in FigureZQ V HAfter use,'or when'it is desired to cleanthe pressure tube It, the instrument is tilted over to the right, Figure 2, preferably until it is horizontal, soas to cause the mercury to flow'back from the pressure tube sure tube to move longitudinally and the valve 6 to close on the seat d, after which saidcap is reversed and screwed into] the position shown in Figure 1 to enable the instrument to be trans,- ported without loss of mercury and'without undue rattling of the-pressure tube It; t

milar washer t It is desirable that a cork or s1 end of thepressure tube It may bearwhenthe f I claim:-- I

ervoir forming one leg and an indicating tube forming the other legwiththebase portion of the casing having a passage interconnecting the lower end adapted to bear against said valve, a

it into the cisternc, the then unscrewed; thus allowing the presshould be arranged in the basal of the casing to provide a resilient pad against which the adjacent 1. All-tube gauge comprising a casing, a resthe casing having a passage interconnecting two- 10 sealing communication. with the cap adapted to threadedly engage the top of the casing to 'force the indicating tube against the valve to unseat the same and place the .tube in V passagein the base portion of the casing.-

2. A U-tube gauge comprising a casing, a. reservoir forming one leg and an indicating tube forming the other leg with the base portion of legs, saidapassage havingavalve seat, a spring pressed valve urged against said valve seat to x close said passage, the indicating tube being lon-- gitudinally movable in said casing with its lower s end adapted to bear against said valve, a cap formed differentially at its opposite ends adapted to threadedly engage the top of the casing, one end of said cap being adapted to force the indicating tube against the valve to unseat the same and place the tube in sealing communication with V the passagein the base portion of the casing, whilst the other end of said cap is adapted, when screwed on to the top of the casing as far as possible, to bear on the adjacent end of the indicating tube and prevent undue movement of the tube but without forcing said tube against the valve to unseat the same.

" FRANK COSSOR. 

